Junction-box.



Patented Mar. 28, 1916.

2 SHEETS-SHEET I.

Fllll- INVENTOR RAD C. W. DAVIS.

JUNCTION BOX.

APPLICATION FILED JAN-11.1913.

1,176,739. Patented Mar. 28,1916.

2 SHEETSSHEET 2.

WI EssEs: I /m w m. BQLMLCCO Qua Atty CHARLES W. DAVIS, OF

EDGEWOBTH, PENNSYLVANIA, ASSIG-NOR TO STANDARD UNDERGROUND CABLECOMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPO- BATION OF PENNSYLVANIA.

JUNCTION-BOX.

Specification of Letters Patent.

Patented Mar. 28, 1916.

Application filed January 11. 1913. Serial No. 741.572.

To all whom it may concern:

Be it known that I, CHARLES W. DAVIS, residing at Edgeworth, in thecounty of Allegheny and State of Pennsylvania, a citizen of the UnitedStates, have invented or discovered certain new and useful Improvementsin J unction-Boxes, of which improvements the following is aspecification.

My present invention relates to junction boxes for electricalinstallations wherein a lurality of service electrical conductors areoined together for the purpose of equalizing or distributing the currentcarried thereby, and for the further purpose of connecting a feed linethereto when necessary or desirable.

The object of my invention is to increase the efficiency and reduce thesize and cost of such boxes.

A further object of my invention is to provide a box which may becompletely assembled for installation in a shop or other suitable placewhere working conditions are more favorable than in a man-hole wheresuch boxes are usually employed. In this further object, my invention issimilar to that described in my Patent No. 1,107,499,

,but differs in the specific means for obtainsuch end.

11 the accompanying drawings, which form part of my specification,Figure 1 is a plan view of a junction box illustrating an embodiment ofmy invention, the lid and insulation cover being removed in this view toshow the interior construction and arrangement of the box; and Figs. 2and 3 are sectional views thereof, taken on the lines 11-11 and III-III,respectively.

Like numerals are used in the several figures to designate like parts.

One feature of my invention consists in providing a junction box of thecharacter and for the purpose described, wherein the several electricalconductors, including the distribution plates or bus-bars, aresurrounded and su ported by an insulation compound which is moldablewhen placed in the box casing, but which subsequently hardens andremains solid under all the heating conditions of service. This featuremay be best understood by describing the manner of manufacturing suchboxes. In the practice of this feature of my invention, I arrange theelectrical conductors, which may consist of studs and leads connectedthereto within a junction box casing in the desired relative positionfor the intended installat1on, and I support the conductors in suchpositlon in any desired manner, but preferably by means of a suitableframe or falsework. The lead ends of the conductors I extend throughsuitable orifices, preferably fluid-tight, in the junction box walls.After thus arranging the electrical conductors, I fill, to the desireddepth, part of the portion of the casing containing the conductors witha hot insulating compound in a plastic or fluid state, which, when itcools and hardens, will be effective to hold, under all conditions ofservice, such conductors in their prearranged positions.

Referring now to the embodiment of my invention shown in the drawings,the side walls of the junction box casing 1 are provided with aplurality of orifices 3, through which flexible leads 2, 2*, etc.,extend, such leads terminating outside of the casing 1. Each lead 2, 2,etc., is connected to one end of a suitable stud or binding post 4, 4",etc., which is provided with a suitable fuse-bar yoke 5 at its oppositeend; also each lead extends through a fluid-tight joint formed by twoclamping plates 6 secured to the outside of the junction box wall, suchclamping plates being adapted to compress a gasket 7 around the leads.The electrical conductors, consisting each of a stud 4 and lead 2, stud4 and lead 2, etc., are then suitably arranged and supported in theirdesired relative positions for service. The support for the electricalconductors may be a skeleton partition of wood 8, or any other suitableinsulating material, such partition resting upon a suitably providedledge 9 formed in the interior of the box; or the several electricalconductors may be suspended in any suitable manner from without thejunction box. Also, distributing plates or bus bars 10, 10, etc., aresuitably supported in desired positions in the same manner as saidelectrical conductors, the arrangement of such plates with relation tothe yoke ends of said studs being such that suitable connecting members,such as the fuse bars 14, may be placed between them as desired. Aftersuch arranging and supporting of the conductors has been effected thecasing is placed preferably in a horizontal position and a hotinsulating compound, of

the character described, is poured or otherwise molded therein until asmuch of the conductors is incased in the compound as is desired. Whensaid conductors are supported by a frame 8, I preferably fill the boxcasing with insulating compound to such a depth that said frame iscompletely covered thereby, as shown in the drawings.

As stated above, the insulating compound which I employ is of such acharacter that when it cools it will harden and form a support for theseveral electrical conductors under all heating conditions of service.Insulating compounds having different physical characteristics may beemployed for this purpose. For example, ll find that the electricalconductors may be suitably molded within an insulating compound, which,when raised to a relatively high degree of temperature, becomes plastic;and among compounds of this character may be named the compound known aselectrose. However, 1 preferably employ a compound which will becomefluid when raised to a relatively high degree of temperature. Suchcompounds are usually largely composed of asphaltum and tars. Somegrades of the compound known as ozite contain relatively largepercentages of asphaltum and tar, and are well adapted for use injunction boxes of the character described. In case it is desirable tohave the exposed ends of. said electrical conductors separated by walls11 of insulating material, as porcelain plates, such plates may bearranged in the desired position before the compound is poured. Thelower edges of these plates will preferably extend for a short distanceinto the compound. Also, in order to completely surround the exposed andbared ends of the conductors with walls of insulation the upper innerwalls of the casing 1 may be suitably lined with plates 12 of insulatingmaterial, as shown, and a removable cover plate 13 of asbestos orporcelain may extend between such conductors and the removable lid.

It will be observed that when thus manufactured the completelyinsulated'junction box has a minimum number of parts, and is thereforecheaper than boxes having more parts for supporting and connecting theelectrical conductors. The box being filled with insulating compound atthe manufacturing plant, all possible precautions may be taken to keepmoisture from the conductors.

Another feature of my invention concerns the particular arrangement orgrouping of electrical conductors of different potentials and phases,whereby the electrical conductors of like potential are grouped forcurrent equalization in one part of the junction box. By sucharrangement, like potential conductors may be placed closely togetherwithout the danger of arcing; and

with the further advantage that the insulation walls, required'betweenconductors of different and of high potentials, may for the most part beeliminated. Having reference now to the drawings, in order to illustratethis feature of my invention I have shown a junction box adapted tounite electrically the common potential conductors of fourfive-wire-twist cables. The leads are arranged in four groups of fiveeach, and the studs are arranged in five groups of four each. One ,ofeach of the four groups of leads is connected to one of each of the fiveroups of studs. In connecting cables of t e character described to theleads, the cable conductors of like potentials are connected to theleads extending. to a single group of studs. As will be seen, a currentdistributing plate is. arranged in suitable relationship to each groupof studs to the end that suitable connections may be made between suchplate and any one of the studs.

lln order to show clearly the illustrative arrangement of the junctionbox parts, the leads in each of the several groups thereof are indicatedby the numerals 2, 2 2*, 2 and 2 the studs bear the same referenceexponent as the leads to which they are connected, that is, the studs 4.are connected to the leads 2, the studs 4 to the leads 2, etc; thestuds having like letter exponents form a single common-potential group;and the current equalization plate for each group bears the same letterexponent as the studs of such groups. As will be readily understood, thelike potential studs of each group may be placed closely togetherwithout danger of arcing from one to the other. Partitions of insulatingmaterial 11 may sepa rate each group of studs so that there will be noarcing between adjacently disposed studs of different potentials. Eachgroup of electrical conductors or leads extending through the wall ofthe casing 1 may be inclosed, and thereby protected, within asupplemental casing 15 such as described in my heretofore mentionedapplication. In Fig. 1 of the drawings, one of such casings is shown insection, the leads inclosed thereby being connected to cable conductorsof a lead sheath cable, which is secured to the outer end of thesupplemental casing by means of a wiped soldered joint.

I claim as my invention:

1. As an article of manufacture, a junction box structure, comprising incombination a casing provided with a plurality of orifices in its walls,a plurality of electrical conductors arranged within said casing andextending through said orifices, current-distributing members arrangedin positions to be electrically connected to said conductors,

ductors, and a body of insulation placed around said conductors and saidmembers,

the removable conductors lying above the surface of said insulation,said insulation being moldable when placed in said casing butsubsequently hardening and holding said conductors and said members intheir arranged positions under all heating conditions of service.

2. As an article of manufacture, a junction box structure comprising incombina tion a casing provided with a plurality of orifices in itswalls, a plurality of leads exdistributing member in their prearrangedpositions under all heating conditions of service. a

3." In an electrical installation the combination of a junction box,conductors of a plurality of multiple conductor cables entering saidbox, the cable conductors of a single cable carrying currents havingdifi'erent potentials but having the same potentials as cable conductorsof another cable, a

body of insulation within said box, a plurality of conducting studsmounted in said insulation and arranged in a plurality of separategroups, an equalizing. conducting element mounted between the studs ofeach of said groups and adapted to be electrically connected thereto,said equalizingelements being separated from each other by theintervalbetween ad acent groups of studs, and

electrical connection means between the studs of a single group and thecommon po}. 1

tential cable conductors,

In testimony whereofI have hereunto set my hand; I p

Y CHARLES W. DAVIS. l

-Witnesses: J H I I ARTHUR A. Annnason, i

Y RALPH B. WILCOX.

